Lens Extenders

Discussion in 'Digital Photography' started by Tumeg101, Oct 27, 2007.

  1. Tumeg101 macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #1
    I have had my camera and 70-300mm sigma lens for about 4 days now, and have noticed 300mm isn't as zoomed in as I thought.. So I looked around, and found some extenders, I am mainly looking at either the sigma 1.4x or 2x extenders.. ($190 or $230) I just have a few questions...

    1) I was just wondering, if these really work, and if they are worth the money...
    2) If I get a sigma extender, will it work with canon lens'?
    3) Will the extender work with macro lens'?
    4) When I buy one, I will be buying from 47th Street Photo, are they trustworthy? Amazons feedback for them is 94% positive, with over 21k reviews... Will I be charged tax when buying from 47th street photo? (they are based in New York and I live in California)

    After comparing the prices, I would say 2x extender is a better buy...
    Please suggest\comment on this, to help me decide which is a better buy, and if an extender is even worth it...
    Can someone maybe post a before, and after extender pictures? Like, get a lens, zoom it out all the way, take a pic... put the extender on, and take the same pic... (1.4x and\or 2x)
     
  2. compuwar macrumors 601

    compuwar

    Joined:
    Oct 5, 2006
    Location:
    Northern/Central VA
    #2
    They're generally refered to as teleconverters, you may find that to be a better Google term in the future...

    Yes, teleconverters work, but as with all things, there are trade-offs (otherwise you'd see lenses go up to half the focal lengths they do.)

    Worth the money depends a lot on the specific application...

    You should get one for whatever lens mount you have. In general, just like lenses the more you spend the better the quality...

    Teleconverters work like extension tubes for macro photography. I don't think they affect the working distance though.

    I only buy from B&H, Adorama, KEH, Calumet or Ace Photo, so I have no idea what anyone outside of those are.

    Ok, now for the trade-offs-

    1. Light.

    A 1.4x teleconverter is generally going to take a full stop of light. A 2x teleconverter is going to take 2 stops of light. That means that on a lens that's f//4, you're going to be at f/5.6 or f/8- many modern cameras don't like to autofocus past f/5.6. If your lens is f/2.8 @300mm, then you'll be at f/4 or f/5.8, if it's slower than 2.8 you'll probably only want to go with the 1.4x.

    2. Quality.

    Extra glass adds distortion to the image. Personally, I only shoot with 1.4x or 1.7x converters with extra-sharp glass to start with. I don't like the quality a 2x converter gives me in generally-- even though I may get acceptable shots from time-to-time. This is somewhat subjective and you'll have to decide what you like. I've see shots with 2x converters that the photographer thought was great that I thought sucked bigtime- so obviously my standards are different than others' may be.

    Also, in general the lens manufacturers make teleconverters that are best used with their lenses (though you can use them with other lenses in a pinch.) With Nikon there are 4-5 different converters for different focal length lenses. You could use a Canon or Nikon telecoverter with a Sigma lens that would fit the respective mount, but the Sigma converter would probably be better matched to the glass. In terms of generic 3rd party TCs, I really like the Kenko 1.4x (which was also branded by Tamron at one point) though these days I tend to shoot with Nikon converters on a Nikon 400.

    Comparison pictures really don't help much without a lot of work, because in general, you're changing both focal length and aperture, so both field of view and depth of field change- you'd really want to be able to matrix out the different possibilities. In general though, TCs are thought of as a compromise and the more magnification, the more degradation and light lost, so you need to decide if you need a 420mm lens or a 600mm lens and if you can shoot at whatever aperture that's going to give you.

    If your lens is the 70-300 f/4-5.6, you're going to have f/8 with a 1.4x converter and f/11 with the 2x. Neither of those is especially good, but I'd say f/11 is probably bordering on useless for most things. Also, don't forget you're going to need heavy support if you're shooting past 1/focal length.
     
  3. Tumeg101 thread starter macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #3
    Umm.. what does this mean? (lol)

    So would you say, at 300mm f/5.6 (yeah I have the lens you thought I did) with the 1.4x, would it still be fast enough to be usable? Or would you just suggest against it, and I most likely will only be using the 1.4x at 100mm-200mm (that is before the 1.4x)
     
  4. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #4
    That's an impossible question to answer: it depends on the amount of light available. The rule of thumb is that to shoot at 300mm you need a shutter speed of 1/300 of a second, or faster. If you are using a 300mm lens with a 1.4x tele-converter then you need to shoot at 1/420 of a second or faster. If your lens is f/5.6 before the tele-converter your fastest aperture will drop to f/8. That will pretty much limit you to outdoors use in the sun.

    You don't say what camera you are using. As noted above many DSLRs will not autofocus of the max aperture is below f/5.6 (all non 1-series Canons for example).
     
  5. Tumeg101 thread starter macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #5
    I have a Rebel XTi,
     
  6. miloblithe macrumors 68020

    miloblithe

    Joined:
    Nov 14, 2003
    Location:
    Washington, DC
    #6
    You got your camera and two lenses four days ago, right? I'd suggest you learn to use what you have for a little while and really learn the strengths and limitations of your setup before you buy more equipment.

    Unless you have unlimited financial resources, wait until you figure out what your priorities might be. Most people would recommend, for instance, that a tripod and flash will be a lot more useful for you than a teleconverter. It's entirely possible that you'd get better results using your current lens on a tripod and cropping than you would using a teleconverter, and the tripod would have other uses beyond that.
     
  7. ChrisA macrumors G4

    Joined:
    Jan 5, 2006
    Location:
    Redondo Beach, California
    #7
    Please tell us what you are photographing. What is the subject? 300mm is a long lens on a crop body. Longer then most people will ever need. But you sound like you must have some specialized use. What that use is may determine if a "teleconverter" is the right thing to get.

    Be warned that there are several things a a teleconverter will do,

    It will reduce the effective aperture by 1 or 2 stops. Remember "f-stop" is diameter over focal length so is you keep the diameter constant and make the length bigger the f ratio changes

    They always have an effect on image quality. Don't expect the image to become sharper.

    For hand holding the rule of thumb is always to keep the shutter a 1/(focal length) or faster. Doubling the length means the slowest shutter speed is cut in half.

    The Auto Focus system in most all cameras can only work with lenses that are f/5.6 or faster. (this is way so many consumer-level lenses are f/5.6) If your lens is already f/5.6 then a 2X converter will make it into a f/11 lens. It will not be able to autofocus. OK maybe it will in very bright light with a high contrast subject but the specs say "no"

    A fast 600mm lens is not cheap and will have a mid four digit price tag. So I can see why you want to go with a teleconverter. If you must, get the 1.4x one it is the best compromise between magnification and bad side effects

    The other option is to simply crop the image. Yes I know "pixels" but the final quality is not much better with a 2x converter then by cropping. What you really need is a $4K lens.
     
  8. ChrisA macrumors G4

    Joined:
    Jan 5, 2006
    Location:
    Redondo Beach, California
    #8
    Seriously, When you see people with lenses past 300mm you see them with very sturdy Bogen or Gitzo tripods Many will put foam pipe insulation over the legs so they can carry over their shoulder. Most with a lens like that are shooting wildlife and will be using a ball head on the tripod. (thats way the bogen or gitzo brand, so they can use interchangeable heads with same legs.)

    Using lenses like these is a very specialized and expensive genre of photography. If they could do it one the cheap with a consumer level lens and TC they would. But no, notice those big white Canon "L" series lenses with the huge front elements.

    Buy the tripod first. A good one will outlast four camera systems, you will have it forever. They have an easy 50 year lifetime. So it is worth $200 or so. Ball heads are another issue, decent ones are not cheap. Get a pan tilt head first you need both and the pan tilt is cheap
     
  9. Tumeg101 thread starter macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #9
    300mm is a long zoom... but it is a sigma lens, and I read that with 3rd party lens' the vision or w\e is 1:2 and canon lens' are 1:1
    So 300mm sigma is actually a 150mm canon lens, that is why I want a teleconverter...

    And about the tripod, I have one but I lost the plate that goes on top that has the screw attached, (the piece that attaches the camera to the tripod)
    I am not missing the whole head, just the plate that comes off with rapid release.. and I was wondering if it was possible to buy one of these separately (I searched and couldn't find any)
    Also, should I get a monopod?? I got one from circuit city, just to see if I want one (if I decide I do, I will return it and buy cheaper from amazon)
    But right now, I am not noticing a difference from hand held to monopod, maybe I am not using it right?
     
  10. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #10
    What, exactly, are you talking about? A 300mm lines is a 300mm lens. It doesn't matter who makes it.
     
  11. Tumeg101 thread starter macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #11
    Yeah it does... according to many people,
    Sigma lens' are 1:2
    Canon is 1:1
     
  12. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #12
    I assume you are talking about this lens. The 1:2 you are talking about is the maximum Macro magnification. This has absolutely nothing to do with focal length. It is still a 300mm lens at the long end. The 1:2 means that in Macro mode you will be able to get objects at half life size or smaller. This is due to minimum focussing distances, not focal length.
     
  13. Westside guy macrumors 601

    Westside guy

    Joined:
    Oct 15, 2003
    Location:
    The soggy side of the Pacific NW
    #13
    Robbieduncan is exactly right - a 300mm lens is going to give you exactly the same magnification / field of view as any other 300mm lens, no matter who makes it. Sometimes it gets slightly more complicated since a non-pro 300mm lens might actually be, at a very close focus distance, more like a 270mm lens because of design trade-offs; but again that's got nothing to do with the brand - Nikon and Canon lenses can have this issue just the same as Sigma or Tokina or Tamron etc.

    I would second the opinion already expressed that you will be better served learning to take photographs with the equipment you now have, doing some reading (and not on forums!) to learn about things like focal length and aperture, and so on. It's pretty obvious there's a lot you don't know - and please believe that's not intended to be insulting or belittling in any way. You need to learn more before you can intelligently make decisions about adding equipment like teleconverters.

    BTW many lenses - especially consumer lenses - will not work with teleconverters for various reasons. The manufacturer will usually have information on a lens' compatibility with teleconverters of various types.
     
  14. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #14
    Very good point. Sigmas list is here. Assuming I linked to the correct lens above then it's not compatible.
     
  15. miloblithe macrumors 68020

    miloblithe

    Joined:
    Nov 14, 2003
    Location:
    Washington, DC
    #15
    You're confusing angle of view (as it relates to a 300mm focal length) with magnification (1:2).

    There are many options of things to buy here, but once again I will suggest that you take pictures for a while before deciding on more things you may or may not need.

    Option one:

    http://www.bhphotovideo.com/bnh/con...(ds)&sq=asc&ac=&bsi=&ci=158&shs=&at=Size_58mm

    Close up filters (lenses). These attach to the front of your 70-300 and allow for closer focusing. Downside? Image quality will be lower (why not just crop).

    Option two:

    Buy an actual macro lens (1:1 magnification).

    Best option:

    Practice with the equipment you have for more than four days.
     
  16. Tumeg101 thread starter macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #16

    About filters, sorry if this is a 'nooby' question but, what does the 'mm' mean for filters?? Would I need a different size for ever lens? (If they are different sizes)
     
  17. seany916 macrumors 6502

    Joined:
    Jun 26, 2006
    Location:
    Southern California
    #17
    Don't use teleconverters. If you have to ask, then don't in this case. You're better off with a sharper picture and cropping if necessary.

    mm for filters refers to the size of the "ring"

    you can use larger filters on smaller lenses, but not the other way around. A step-down ring will cost around $5-12 depending on what you get. Just make sure you don't strip the threads and you'll be fine.

    Some people recommend getting one size filters and gettting different sized step down rings as needed. Cheaper than buying different filters in different sizes. Many people I know standardize on 72mm for their filters, but that may not be the best for your needs.

    Before going out and spending a fortune on equipment, learn how to set shutter speed, aperture, ISO to get the results that reflect the "shot" that you want to share with the world.

    But your money, do what you want with it.

    Consider spending money on camera classes. That knowledge will carry over with you to any camera you use for the rest of your life. Equipment will become old and obsolete over time.

    noob with D40 w/ kit lens & $5,000 in photography classes and tons of practice
    vs.
    gearhead noob with D3 with every high end lens Nikon makes, that doesn' want to learn how to use the camera, but knows all the specifications of the latest and greatest gear

    Who would you put your money on in a photography contest?

    If you've got the money, take the classes. It'll help you to better understand photography and your needs. The needs of pro photographers don't necessarily meet YOUR needs.
     
  18. miloblithe macrumors 68020

    miloblithe

    Joined:
    Nov 14, 2003
    Location:
    Washington, DC
    #18
    It's the diameter of the screw-in ring on the front of the lens. The Sigma you have is 58mm, which is why I linked to 58mm close up filters. The kit lens you have is, I think, 52mm. 52mm is usually the smallest, although 49mm lenses aren't rare and smaller lenses exist for smaller formats. The rings rarely are bigger than 82mm, but some giant telephoto lenses get much bigger than that.

    But please, listen to us, go to your library and take out every book you can on photography and start reading. This will improve your results much faster than buying new gear or starting new threads. Pay attention in photography class, and experiment. Take tons of pictures. Try different settings when you do. Look at the EXIF data when you review your pictures. Learn what works for you.

    You have more than enough equipment to learn with for the time being. Concentrate on that.
     
  19. Cave Man macrumors 604

    Cave Man

    #19
    Probably not for that lens. IQ will diminish and you'll lose autofocus. Their 1.4x works extremely well with my Sigma 100-300 f/4, and the 2x works extremely well with my EF 200mm f/2.8L.

    It'll work with some of the longer zooms and teles, but not with the "normal" or wide-angle lenses. The Sigma TC are engineered similar to Canons, with a protruding front element that only works on lenses with recessed rear elements. This improves the IQ of TCs.

    It depends on the macro lens. They both work with my Sigma 105 and 150 macros on my 30D.

    I've had good luck with 47th, but they sell gray market. The quality is the same, but since Sigma's 1.4x and 2x TC are part of their EX line, they will only come with 1 year warranties through 47th Street, as opposed to the 4 year warranty for non-gray market EX lenses through Sigma USA. You shouldn't have to pay taxes, unless 47th or Amazon is taxed by California.

    I wouldn't put a 2x TC on any telezoom lens; I'd only use it for fixed-FL lenses that are already of high quality.
     
  20. colinmack macrumors regular

    Joined:
    Feb 25, 2006
    #20
    I'll throw in my opinion based on the discussion so far:

    - don't buy a teleconverter
    - buy a decent tripod
    - if you want more apparent zoom/magnification, shoot at 300mm and crop
    - four days isn't anywhere near enough time to get used to your gear
    - before you invest in anything else, shoot for 2-3 months and analyze your shooting patterns: are there focal ranges you find you are missing, do you find yourself bumping up against the wide or long end of your range, pictures you felt you missed because of not having the right lens or more light or a stronger flash, etc. (something like ExposurePlot might help a lot here)

    Cheers, Colin.
     
  21. Tumeg101 thread starter macrumors 6502a

    Tumeg101

    Joined:
    Jun 30, 2007
    Location:
    Orange County, California
    #21
    I am already taking classes,
    I am learning how to set the aperture\iso ect. for good shots,

    I have ordered a "starter kit" that has a nice canon case, 72mm uv protection filter, and a extra batter... so will the 72mm uv filter fit both my lens'?

    I have now decided on not getting a teleconverter, so yeah.. thanks everyone!
     
  22. Lovesong macrumors 65816

    Lovesong

    Joined:
    Sep 15, 2006
    Location:
    Stuck beween a rock and a hard place
  23. Cave Man macrumors 604

    Cave Man

    #23
    Personally, I avoid filters. The only ones I use are circular polarizers, neutral density and gradient ND filters. Your money would be better spent on lens hoods, IMO. I've been doing photography for nearly 30 years and I've never damaged the front element of a lens with a hood on.
     

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